1/* //device/extlibs/pv/android/AudioTrack.cpp
2**
3** Copyright 2007, The Android Open Source Project
4**
5** Licensed under the Apache License, Version 2.0 (the "License");
6** you may not use this file except in compliance with the License.
7** You may obtain a copy of the License at
8**
9**     http://www.apache.org/licenses/LICENSE-2.0
10**
11** Unless required by applicable law or agreed to in writing, software
12** distributed under the License is distributed on an "AS IS" BASIS,
13** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14** See the License for the specific language governing permissions and
15** limitations under the License.
16*/
17
18
19//#define LOG_NDEBUG 0
20#define LOG_TAG "AudioTrack"
21
22#include <stdint.h>
23#include <sys/types.h>
24#include <limits.h>
25
26#include <sched.h>
27#include <sys/resource.h>
28
29#include <private/media/AudioTrackShared.h>
30
31#include <media/AudioSystem.h>
32#include <media/AudioTrack.h>
33
34#include <utils/Log.h>
35#include <binder/Parcel.h>
36#include <binder/IPCThreadState.h>
37#include <utils/Timers.h>
38#include <utils/Atomic.h>
39
40#include <cutils/bitops.h>
41
42#include <system/audio.h>
43#include <system/audio_policy.h>
44
45#define LIKELY( exp )       (__builtin_expect( (exp) != 0, true  ))
46#define UNLIKELY( exp )     (__builtin_expect( (exp) != 0, false ))
47
48namespace android {
49// ---------------------------------------------------------------------------
50
51// static
52status_t AudioTrack::getMinFrameCount(
53        int* frameCount,
54        int streamType,
55        uint32_t sampleRate)
56{
57    int afSampleRate;
58    if (AudioSystem::getOutputSamplingRate(&afSampleRate, streamType) != NO_ERROR) {
59        return NO_INIT;
60    }
61    int afFrameCount;
62    if (AudioSystem::getOutputFrameCount(&afFrameCount, streamType) != NO_ERROR) {
63        return NO_INIT;
64    }
65    uint32_t afLatency;
66    if (AudioSystem::getOutputLatency(&afLatency, streamType) != NO_ERROR) {
67        return NO_INIT;
68    }
69
70    // Ensure that buffer depth covers at least audio hardware latency
71    uint32_t minBufCount = afLatency / ((1000 * afFrameCount) / afSampleRate);
72    if (minBufCount < 2) minBufCount = 2;
73
74    *frameCount = (sampleRate == 0) ? afFrameCount * minBufCount :
75              afFrameCount * minBufCount * sampleRate / afSampleRate;
76    return NO_ERROR;
77}
78
79// ---------------------------------------------------------------------------
80
81AudioTrack::AudioTrack()
82    : mStatus(NO_INIT)
83{
84}
85
86AudioTrack::AudioTrack(
87        int streamType,
88        uint32_t sampleRate,
89        int format,
90        int channelMask,
91        int frameCount,
92        uint32_t flags,
93        callback_t cbf,
94        void* user,
95        int notificationFrames,
96        int sessionId)
97    : mStatus(NO_INIT)
98{
99    mStatus = set(streamType, sampleRate, format, channelMask,
100            frameCount, flags, cbf, user, notificationFrames,
101            0, false, sessionId);
102}
103
104AudioTrack::AudioTrack(
105        int streamType,
106        uint32_t sampleRate,
107        int format,
108        int channelMask,
109        const sp<IMemory>& sharedBuffer,
110        uint32_t flags,
111        callback_t cbf,
112        void* user,
113        int notificationFrames,
114        int sessionId)
115    : mStatus(NO_INIT)
116{
117    mStatus = set(streamType, sampleRate, format, channelMask,
118            0, flags, cbf, user, notificationFrames,
119            sharedBuffer, false, sessionId);
120}
121
122AudioTrack::~AudioTrack()
123{
124    LOGV_IF(mSharedBuffer != 0, "Destructor sharedBuffer: %p", mSharedBuffer->pointer());
125
126    if (mStatus == NO_ERROR) {
127        // Make sure that callback function exits in the case where
128        // it is looping on buffer full condition in obtainBuffer().
129        // Otherwise the callback thread will never exit.
130        stop();
131        if (mAudioTrackThread != 0) {
132            mAudioTrackThread->requestExitAndWait();
133            mAudioTrackThread.clear();
134        }
135        mAudioTrack.clear();
136        IPCThreadState::self()->flushCommands();
137        AudioSystem::releaseAudioSessionId(mSessionId);
138    }
139}
140
141status_t AudioTrack::set(
142        int streamType,
143        uint32_t sampleRate,
144        int format,
145        int channelMask,
146        int frameCount,
147        uint32_t flags,
148        callback_t cbf,
149        void* user,
150        int notificationFrames,
151        const sp<IMemory>& sharedBuffer,
152        bool threadCanCallJava,
153        int sessionId)
154{
155
156    LOGV_IF(sharedBuffer != 0, "sharedBuffer: %p, size: %d", sharedBuffer->pointer(), sharedBuffer->size());
157
158    AutoMutex lock(mLock);
159    if (mAudioTrack != 0) {
160        LOGE("Track already in use");
161        return INVALID_OPERATION;
162    }
163
164    int afSampleRate;
165    if (AudioSystem::getOutputSamplingRate(&afSampleRate, streamType) != NO_ERROR) {
166        return NO_INIT;
167    }
168    uint32_t afLatency;
169    if (AudioSystem::getOutputLatency(&afLatency, streamType) != NO_ERROR) {
170        return NO_INIT;
171    }
172
173    // handle default values first.
174    if (streamType == AUDIO_STREAM_DEFAULT) {
175        streamType = AUDIO_STREAM_MUSIC;
176    }
177    if (sampleRate == 0) {
178        sampleRate = afSampleRate;
179    }
180    // these below should probably come from the audioFlinger too...
181    if (format == 0) {
182        format = AUDIO_FORMAT_PCM_16_BIT;
183    }
184    if (channelMask == 0) {
185        channelMask = AUDIO_CHANNEL_OUT_STEREO;
186    }
187
188    // validate parameters
189    if (!audio_is_valid_format(format)) {
190        LOGE("Invalid format");
191        return BAD_VALUE;
192    }
193
194    // force direct flag if format is not linear PCM
195    if (!audio_is_linear_pcm(format)) {
196        flags |= AUDIO_POLICY_OUTPUT_FLAG_DIRECT;
197    }
198
199    if (!audio_is_output_channel(channelMask)) {
200        LOGE("Invalid channel mask");
201        return BAD_VALUE;
202    }
203    uint32_t channelCount = popcount(channelMask);
204
205    audio_io_handle_t output = AudioSystem::getOutput(
206                                    (audio_stream_type_t)streamType,
207                                    sampleRate,format, channelMask,
208                                    (audio_policy_output_flags_t)flags);
209
210    if (output == 0) {
211        LOGE("Could not get audio output for stream type %d", streamType);
212        return BAD_VALUE;
213    }
214
215    mVolume[LEFT] = 1.0f;
216    mVolume[RIGHT] = 1.0f;
217    mSendLevel = 0;
218    mFrameCount = frameCount;
219    mNotificationFramesReq = notificationFrames;
220    mSessionId = sessionId;
221    mAuxEffectId = 0;
222
223    // create the IAudioTrack
224    status_t status = createTrack_l(streamType,
225                                  sampleRate,
226                                  (uint32_t)format,
227                                  (uint32_t)channelMask,
228                                  frameCount,
229                                  flags,
230                                  sharedBuffer,
231                                  output,
232                                  true);
233
234    if (status != NO_ERROR) {
235        return status;
236    }
237
238    if (cbf != 0) {
239        mAudioTrackThread = new AudioTrackThread(*this, threadCanCallJava);
240        if (mAudioTrackThread == 0) {
241          LOGE("Could not create callback thread");
242          return NO_INIT;
243        }
244    }
245
246    mStatus = NO_ERROR;
247
248    mStreamType = streamType;
249    mFormat = (uint32_t)format;
250    mChannelMask = (uint32_t)channelMask;
251    mChannelCount = channelCount;
252    mSharedBuffer = sharedBuffer;
253    mMuted = false;
254    mActive = 0;
255    mCbf = cbf;
256    mUserData = user;
257    mLoopCount = 0;
258    mMarkerPosition = 0;
259    mMarkerReached = false;
260    mNewPosition = 0;
261    mUpdatePeriod = 0;
262    mFlushed = false;
263    mFlags = flags;
264    AudioSystem::acquireAudioSessionId(mSessionId);
265    mRestoreStatus = NO_ERROR;
266    return NO_ERROR;
267}
268
269status_t AudioTrack::initCheck() const
270{
271    return mStatus;
272}
273
274// -------------------------------------------------------------------------
275
276uint32_t AudioTrack::latency() const
277{
278    return mLatency;
279}
280
281int AudioTrack::streamType() const
282{
283    return mStreamType;
284}
285
286int AudioTrack::format() const
287{
288    return mFormat;
289}
290
291int AudioTrack::channelCount() const
292{
293    return mChannelCount;
294}
295
296uint32_t AudioTrack::frameCount() const
297{
298    return mCblk->frameCount;
299}
300
301int AudioTrack::frameSize() const
302{
303    if (audio_is_linear_pcm(mFormat)) {
304        return channelCount()*audio_bytes_per_sample(mFormat);
305    } else {
306        return sizeof(uint8_t);
307    }
308}
309
310sp<IMemory>& AudioTrack::sharedBuffer()
311{
312    return mSharedBuffer;
313}
314
315// -------------------------------------------------------------------------
316
317void AudioTrack::start()
318{
319    sp<AudioTrackThread> t = mAudioTrackThread;
320    status_t status = NO_ERROR;
321
322    LOGV("start %p", this);
323    if (t != 0) {
324        if (t->exitPending()) {
325            if (t->requestExitAndWait() == WOULD_BLOCK) {
326                LOGE("AudioTrack::start called from thread");
327                return;
328            }
329        }
330        t->mLock.lock();
331     }
332
333    AutoMutex lock(mLock);
334    // acquire a strong reference on the IMemory and IAudioTrack so that they cannot be destroyed
335    // while we are accessing the cblk
336    sp <IAudioTrack> audioTrack = mAudioTrack;
337    sp <IMemory> iMem = mCblkMemory;
338    audio_track_cblk_t* cblk = mCblk;
339
340    if (mActive == 0) {
341        mFlushed = false;
342        mActive = 1;
343        mNewPosition = cblk->server + mUpdatePeriod;
344        cblk->lock.lock();
345        cblk->bufferTimeoutMs = MAX_STARTUP_TIMEOUT_MS;
346        cblk->waitTimeMs = 0;
347        android_atomic_and(~CBLK_DISABLED_ON, &cblk->flags);
348        if (t != 0) {
349           t->run("AudioTrackThread", ANDROID_PRIORITY_AUDIO);
350        } else {
351            setpriority(PRIO_PROCESS, 0, ANDROID_PRIORITY_AUDIO);
352        }
353
354        LOGV("start %p before lock cblk %p", this, mCblk);
355        if (!(cblk->flags & CBLK_INVALID_MSK)) {
356            cblk->lock.unlock();
357            status = mAudioTrack->start();
358            cblk->lock.lock();
359            if (status == DEAD_OBJECT) {
360                android_atomic_or(CBLK_INVALID_ON, &cblk->flags);
361            }
362        }
363        if (cblk->flags & CBLK_INVALID_MSK) {
364            status = restoreTrack_l(cblk, true);
365        }
366        cblk->lock.unlock();
367        if (status != NO_ERROR) {
368            LOGV("start() failed");
369            mActive = 0;
370            if (t != 0) {
371                t->requestExit();
372            } else {
373                setpriority(PRIO_PROCESS, 0, ANDROID_PRIORITY_NORMAL);
374            }
375        }
376    }
377
378    if (t != 0) {
379        t->mLock.unlock();
380    }
381}
382
383void AudioTrack::stop()
384{
385    sp<AudioTrackThread> t = mAudioTrackThread;
386
387    LOGV("stop %p", this);
388    if (t != 0) {
389        t->mLock.lock();
390    }
391
392    AutoMutex lock(mLock);
393    if (mActive == 1) {
394        mActive = 0;
395        mCblk->cv.signal();
396        mAudioTrack->stop();
397        // Cancel loops (If we are in the middle of a loop, playback
398        // would not stop until loopCount reaches 0).
399        setLoop_l(0, 0, 0);
400        // the playback head position will reset to 0, so if a marker is set, we need
401        // to activate it again
402        mMarkerReached = false;
403        // Force flush if a shared buffer is used otherwise audioflinger
404        // will not stop before end of buffer is reached.
405        if (mSharedBuffer != 0) {
406            flush_l();
407        }
408        if (t != 0) {
409            t->requestExit();
410        } else {
411            setpriority(PRIO_PROCESS, 0, ANDROID_PRIORITY_NORMAL);
412        }
413    }
414
415    if (t != 0) {
416        t->mLock.unlock();
417    }
418}
419
420bool AudioTrack::stopped() const
421{
422    return !mActive;
423}
424
425void AudioTrack::flush()
426{
427    AutoMutex lock(mLock);
428    flush_l();
429}
430
431// must be called with mLock held
432void AudioTrack::flush_l()
433{
434    LOGV("flush");
435
436    // clear playback marker and periodic update counter
437    mMarkerPosition = 0;
438    mMarkerReached = false;
439    mUpdatePeriod = 0;
440
441    if (!mActive) {
442        mFlushed = true;
443        mAudioTrack->flush();
444        // Release AudioTrack callback thread in case it was waiting for new buffers
445        // in AudioTrack::obtainBuffer()
446        mCblk->cv.signal();
447    }
448}
449
450void AudioTrack::pause()
451{
452    LOGV("pause");
453    AutoMutex lock(mLock);
454    if (mActive == 1) {
455        mActive = 0;
456        mAudioTrack->pause();
457    }
458}
459
460void AudioTrack::mute(bool e)
461{
462    mAudioTrack->mute(e);
463    mMuted = e;
464}
465
466bool AudioTrack::muted() const
467{
468    return mMuted;
469}
470
471status_t AudioTrack::setVolume(float left, float right)
472{
473    if (left > 1.0f || right > 1.0f) {
474        return BAD_VALUE;
475    }
476
477    AutoMutex lock(mLock);
478    mVolume[LEFT] = left;
479    mVolume[RIGHT] = right;
480
481    // write must be atomic
482    mCblk->volumeLR = (uint32_t(uint16_t(right * 0x1000)) << 16) | uint16_t(left * 0x1000);
483
484    return NO_ERROR;
485}
486
487void AudioTrack::getVolume(float* left, float* right)
488{
489    if (left != NULL) {
490        *left  = mVolume[LEFT];
491    }
492    if (right != NULL) {
493        *right = mVolume[RIGHT];
494    }
495}
496
497status_t AudioTrack::setAuxEffectSendLevel(float level)
498{
499    LOGV("setAuxEffectSendLevel(%f)", level);
500    if (level > 1.0f) {
501        return BAD_VALUE;
502    }
503    AutoMutex lock(mLock);
504
505    mSendLevel = level;
506
507    mCblk->sendLevel = uint16_t(level * 0x1000);
508
509    return NO_ERROR;
510}
511
512void AudioTrack::getAuxEffectSendLevel(float* level)
513{
514    if (level != NULL) {
515        *level  = mSendLevel;
516    }
517}
518
519status_t AudioTrack::setSampleRate(int rate)
520{
521    int afSamplingRate;
522
523    if (AudioSystem::getOutputSamplingRate(&afSamplingRate, mStreamType) != NO_ERROR) {
524        return NO_INIT;
525    }
526    // Resampler implementation limits input sampling rate to 2 x output sampling rate.
527    if (rate <= 0 || rate > afSamplingRate*2 ) return BAD_VALUE;
528
529    AutoMutex lock(mLock);
530    mCblk->sampleRate = rate;
531    return NO_ERROR;
532}
533
534uint32_t AudioTrack::getSampleRate()
535{
536    AutoMutex lock(mLock);
537    return mCblk->sampleRate;
538}
539
540status_t AudioTrack::setLoop(uint32_t loopStart, uint32_t loopEnd, int loopCount)
541{
542    AutoMutex lock(mLock);
543    return setLoop_l(loopStart, loopEnd, loopCount);
544}
545
546// must be called with mLock held
547status_t AudioTrack::setLoop_l(uint32_t loopStart, uint32_t loopEnd, int loopCount)
548{
549    audio_track_cblk_t* cblk = mCblk;
550
551    Mutex::Autolock _l(cblk->lock);
552
553    if (loopCount == 0) {
554        cblk->loopStart = UINT_MAX;
555        cblk->loopEnd = UINT_MAX;
556        cblk->loopCount = 0;
557        mLoopCount = 0;
558        return NO_ERROR;
559    }
560
561    if (loopStart >= loopEnd ||
562        loopEnd - loopStart > cblk->frameCount ||
563        cblk->server > loopStart) {
564        LOGE("setLoop invalid value: loopStart %d, loopEnd %d, loopCount %d, framecount %d, user %d", loopStart, loopEnd, loopCount, cblk->frameCount, cblk->user);
565        return BAD_VALUE;
566    }
567
568    if ((mSharedBuffer != 0) && (loopEnd > cblk->frameCount)) {
569        LOGE("setLoop invalid value: loop markers beyond data: loopStart %d, loopEnd %d, framecount %d",
570            loopStart, loopEnd, cblk->frameCount);
571        return BAD_VALUE;
572    }
573
574    cblk->loopStart = loopStart;
575    cblk->loopEnd = loopEnd;
576    cblk->loopCount = loopCount;
577    mLoopCount = loopCount;
578
579    return NO_ERROR;
580}
581
582status_t AudioTrack::getLoop(uint32_t *loopStart, uint32_t *loopEnd, int *loopCount)
583{
584    AutoMutex lock(mLock);
585    if (loopStart != 0) {
586        *loopStart = mCblk->loopStart;
587    }
588    if (loopEnd != 0) {
589        *loopEnd = mCblk->loopEnd;
590    }
591    if (loopCount != 0) {
592        if (mCblk->loopCount < 0) {
593            *loopCount = -1;
594        } else {
595            *loopCount = mCblk->loopCount;
596        }
597    }
598
599    return NO_ERROR;
600}
601
602status_t AudioTrack::setMarkerPosition(uint32_t marker)
603{
604    if (mCbf == 0) return INVALID_OPERATION;
605
606    mMarkerPosition = marker;
607    mMarkerReached = false;
608
609    return NO_ERROR;
610}
611
612status_t AudioTrack::getMarkerPosition(uint32_t *marker)
613{
614    if (marker == 0) return BAD_VALUE;
615
616    *marker = mMarkerPosition;
617
618    return NO_ERROR;
619}
620
621status_t AudioTrack::setPositionUpdatePeriod(uint32_t updatePeriod)
622{
623    if (mCbf == 0) return INVALID_OPERATION;
624
625    uint32_t curPosition;
626    getPosition(&curPosition);
627    mNewPosition = curPosition + updatePeriod;
628    mUpdatePeriod = updatePeriod;
629
630    return NO_ERROR;
631}
632
633status_t AudioTrack::getPositionUpdatePeriod(uint32_t *updatePeriod)
634{
635    if (updatePeriod == 0) return BAD_VALUE;
636
637    *updatePeriod = mUpdatePeriod;
638
639    return NO_ERROR;
640}
641
642status_t AudioTrack::setPosition(uint32_t position)
643{
644    AutoMutex lock(mLock);
645    Mutex::Autolock _l(mCblk->lock);
646
647    if (!stopped()) return INVALID_OPERATION;
648
649    if (position > mCblk->user) return BAD_VALUE;
650
651    mCblk->server = position;
652    android_atomic_or(CBLK_FORCEREADY_ON, &mCblk->flags);
653
654    return NO_ERROR;
655}
656
657status_t AudioTrack::getPosition(uint32_t *position)
658{
659    if (position == 0) return BAD_VALUE;
660    AutoMutex lock(mLock);
661    *position = mFlushed ? 0 : mCblk->server;
662
663    return NO_ERROR;
664}
665
666status_t AudioTrack::reload()
667{
668    AutoMutex lock(mLock);
669
670    if (!stopped()) return INVALID_OPERATION;
671
672    flush_l();
673
674    mCblk->stepUser(mCblk->frameCount);
675
676    return NO_ERROR;
677}
678
679audio_io_handle_t AudioTrack::getOutput()
680{
681    AutoMutex lock(mLock);
682    return getOutput_l();
683}
684
685// must be called with mLock held
686audio_io_handle_t AudioTrack::getOutput_l()
687{
688    return AudioSystem::getOutput((audio_stream_type_t)mStreamType,
689            mCblk->sampleRate, mFormat, mChannelMask, (audio_policy_output_flags_t)mFlags);
690}
691
692int AudioTrack::getSessionId()
693{
694    return mSessionId;
695}
696
697status_t AudioTrack::attachAuxEffect(int effectId)
698{
699    LOGV("attachAuxEffect(%d)", effectId);
700    status_t status = mAudioTrack->attachAuxEffect(effectId);
701    if (status == NO_ERROR) {
702        mAuxEffectId = effectId;
703    }
704    return status;
705}
706
707// -------------------------------------------------------------------------
708
709// must be called with mLock held
710status_t AudioTrack::createTrack_l(
711        int streamType,
712        uint32_t sampleRate,
713        uint32_t format,
714        uint32_t channelMask,
715        int frameCount,
716        uint32_t flags,
717        const sp<IMemory>& sharedBuffer,
718        audio_io_handle_t output,
719        bool enforceFrameCount)
720{
721    status_t status;
722    const sp<IAudioFlinger>& audioFlinger = AudioSystem::get_audio_flinger();
723    if (audioFlinger == 0) {
724       LOGE("Could not get audioflinger");
725       return NO_INIT;
726    }
727
728    int afSampleRate;
729    if (AudioSystem::getOutputSamplingRate(&afSampleRate, streamType) != NO_ERROR) {
730        return NO_INIT;
731    }
732    int afFrameCount;
733    if (AudioSystem::getOutputFrameCount(&afFrameCount, streamType) != NO_ERROR) {
734        return NO_INIT;
735    }
736    uint32_t afLatency;
737    if (AudioSystem::getOutputLatency(&afLatency, streamType) != NO_ERROR) {
738        return NO_INIT;
739    }
740
741    mNotificationFramesAct = mNotificationFramesReq;
742    if (!audio_is_linear_pcm(format)) {
743        if (sharedBuffer != 0) {
744            frameCount = sharedBuffer->size();
745        }
746    } else {
747        // Ensure that buffer depth covers at least audio hardware latency
748        uint32_t minBufCount = afLatency / ((1000 * afFrameCount)/afSampleRate);
749        if (minBufCount < 2) minBufCount = 2;
750
751        int minFrameCount = (afFrameCount*sampleRate*minBufCount)/afSampleRate;
752
753        if (sharedBuffer == 0) {
754            if (frameCount == 0) {
755                frameCount = minFrameCount;
756            }
757            if (mNotificationFramesAct == 0) {
758                mNotificationFramesAct = frameCount/2;
759            }
760            // Make sure that application is notified with sufficient margin
761            // before underrun
762            if (mNotificationFramesAct > (uint32_t)frameCount/2) {
763                mNotificationFramesAct = frameCount/2;
764            }
765            if (frameCount < minFrameCount) {
766                LOGW_IF(enforceFrameCount, "Minimum buffer size corrected from %d to %d",
767                         frameCount, minFrameCount);
768                frameCount = minFrameCount;
769            }
770        } else {
771            // Ensure that buffer alignment matches channelcount
772            int channelCount = popcount(channelMask);
773            if (((uint32_t)sharedBuffer->pointer() & (channelCount | 1)) != 0) {
774                LOGE("Invalid buffer alignement: address %p, channelCount %d", sharedBuffer->pointer(), channelCount);
775                return BAD_VALUE;
776            }
777            frameCount = sharedBuffer->size()/channelCount/sizeof(int16_t);
778        }
779    }
780
781    sp<IAudioTrack> track = audioFlinger->createTrack(getpid(),
782                                                      streamType,
783                                                      sampleRate,
784                                                      format,
785                                                      channelMask,
786                                                      frameCount,
787                                                      ((uint16_t)flags) << 16,
788                                                      sharedBuffer,
789                                                      output,
790                                                      &mSessionId,
791                                                      &status);
792
793    if (track == 0) {
794        LOGE("AudioFlinger could not create track, status: %d", status);
795        return status;
796    }
797    sp<IMemory> cblk = track->getCblk();
798    if (cblk == 0) {
799        LOGE("Could not get control block");
800        return NO_INIT;
801    }
802    mAudioTrack.clear();
803    mAudioTrack = track;
804    mCblkMemory.clear();
805    mCblkMemory = cblk;
806    mCblk = static_cast<audio_track_cblk_t*>(cblk->pointer());
807    android_atomic_or(CBLK_DIRECTION_OUT, &mCblk->flags);
808    if (sharedBuffer == 0) {
809        mCblk->buffers = (char*)mCblk + sizeof(audio_track_cblk_t);
810    } else {
811        mCblk->buffers = sharedBuffer->pointer();
812         // Force buffer full condition as data is already present in shared memory
813        mCblk->stepUser(mCblk->frameCount);
814    }
815
816    mCblk->volumeLR = (uint32_t(uint16_t(mVolume[RIGHT] * 0x1000)) << 16) | uint16_t(mVolume[LEFT] * 0x1000);
817    mCblk->sendLevel = uint16_t(mSendLevel * 0x1000);
818    mAudioTrack->attachAuxEffect(mAuxEffectId);
819    mCblk->bufferTimeoutMs = MAX_STARTUP_TIMEOUT_MS;
820    mCblk->waitTimeMs = 0;
821    mRemainingFrames = mNotificationFramesAct;
822    mLatency = afLatency + (1000*mCblk->frameCount) / sampleRate;
823    return NO_ERROR;
824}
825
826status_t AudioTrack::obtainBuffer(Buffer* audioBuffer, int32_t waitCount)
827{
828    AutoMutex lock(mLock);
829    int active;
830    status_t result = NO_ERROR;
831    audio_track_cblk_t* cblk = mCblk;
832    uint32_t framesReq = audioBuffer->frameCount;
833    uint32_t waitTimeMs = (waitCount < 0) ? cblk->bufferTimeoutMs : WAIT_PERIOD_MS;
834
835    audioBuffer->frameCount  = 0;
836    audioBuffer->size = 0;
837
838    uint32_t framesAvail = cblk->framesAvailable();
839
840    cblk->lock.lock();
841    if (cblk->flags & CBLK_INVALID_MSK) {
842        goto create_new_track;
843    }
844    cblk->lock.unlock();
845
846    if (framesAvail == 0) {
847        cblk->lock.lock();
848        goto start_loop_here;
849        while (framesAvail == 0) {
850            active = mActive;
851            if (UNLIKELY(!active)) {
852                LOGV("Not active and NO_MORE_BUFFERS");
853                cblk->lock.unlock();
854                return NO_MORE_BUFFERS;
855            }
856            if (UNLIKELY(!waitCount)) {
857                cblk->lock.unlock();
858                return WOULD_BLOCK;
859            }
860            if (!(cblk->flags & CBLK_INVALID_MSK)) {
861                mLock.unlock();
862                result = cblk->cv.waitRelative(cblk->lock, milliseconds(waitTimeMs));
863                cblk->lock.unlock();
864                mLock.lock();
865                if (mActive == 0) {
866                    return status_t(STOPPED);
867                }
868                cblk->lock.lock();
869            }
870
871            if (cblk->flags & CBLK_INVALID_MSK) {
872                goto create_new_track;
873            }
874            if (__builtin_expect(result!=NO_ERROR, false)) {
875                cblk->waitTimeMs += waitTimeMs;
876                if (cblk->waitTimeMs >= cblk->bufferTimeoutMs) {
877                    // timing out when a loop has been set and we have already written upto loop end
878                    // is a normal condition: no need to wake AudioFlinger up.
879                    if (cblk->user < cblk->loopEnd) {
880                        LOGW(   "obtainBuffer timed out (is the CPU pegged?) %p "
881                                "user=%08x, server=%08x", this, cblk->user, cblk->server);
882                        //unlock cblk mutex before calling mAudioTrack->start() (see issue #1617140)
883                        cblk->lock.unlock();
884                        result = mAudioTrack->start();
885                        cblk->lock.lock();
886                        if (result == DEAD_OBJECT) {
887                            android_atomic_or(CBLK_INVALID_ON, &cblk->flags);
888create_new_track:
889                            result = restoreTrack_l(cblk, false);
890                        }
891                        if (result != NO_ERROR) {
892                            LOGW("obtainBuffer create Track error %d", result);
893                            cblk->lock.unlock();
894                            return result;
895                        }
896                    }
897                    cblk->waitTimeMs = 0;
898                }
899
900                if (--waitCount == 0) {
901                    cblk->lock.unlock();
902                    return TIMED_OUT;
903                }
904            }
905            // read the server count again
906        start_loop_here:
907            framesAvail = cblk->framesAvailable_l();
908        }
909        cblk->lock.unlock();
910    }
911
912    // restart track if it was disabled by audioflinger due to previous underrun
913    if (mActive && (cblk->flags & CBLK_DISABLED_MSK)) {
914        android_atomic_and(~CBLK_DISABLED_ON, &cblk->flags);
915        LOGW("obtainBuffer() track %p disabled, restarting", this);
916        mAudioTrack->start();
917    }
918
919    cblk->waitTimeMs = 0;
920
921    if (framesReq > framesAvail) {
922        framesReq = framesAvail;
923    }
924
925    uint32_t u = cblk->user;
926    uint32_t bufferEnd = cblk->userBase + cblk->frameCount;
927
928    if (u + framesReq > bufferEnd) {
929        framesReq = bufferEnd - u;
930    }
931
932    audioBuffer->flags = mMuted ? Buffer::MUTE : 0;
933    audioBuffer->channelCount = mChannelCount;
934    audioBuffer->frameCount = framesReq;
935    audioBuffer->size = framesReq * cblk->frameSize;
936    if (audio_is_linear_pcm(mFormat)) {
937        audioBuffer->format = AUDIO_FORMAT_PCM_16_BIT;
938    } else {
939        audioBuffer->format = mFormat;
940    }
941    audioBuffer->raw = (int8_t *)cblk->buffer(u);
942    active = mActive;
943    return active ? status_t(NO_ERROR) : status_t(STOPPED);
944}
945
946void AudioTrack::releaseBuffer(Buffer* audioBuffer)
947{
948    AutoMutex lock(mLock);
949    mCblk->stepUser(audioBuffer->frameCount);
950}
951
952// -------------------------------------------------------------------------
953
954ssize_t AudioTrack::write(const void* buffer, size_t userSize)
955{
956
957    if (mSharedBuffer != 0) return INVALID_OPERATION;
958
959    if (ssize_t(userSize) < 0) {
960        // sanity-check. user is most-likely passing an error code.
961        LOGE("AudioTrack::write(buffer=%p, size=%u (%d)",
962                buffer, userSize, userSize);
963        return BAD_VALUE;
964    }
965
966    LOGV("write %p: %d bytes, mActive=%d", this, userSize, mActive);
967
968    // acquire a strong reference on the IMemory and IAudioTrack so that they cannot be destroyed
969    // while we are accessing the cblk
970    mLock.lock();
971    sp <IAudioTrack> audioTrack = mAudioTrack;
972    sp <IMemory> iMem = mCblkMemory;
973    mLock.unlock();
974
975    ssize_t written = 0;
976    const int8_t *src = (const int8_t *)buffer;
977    Buffer audioBuffer;
978    size_t frameSz = (size_t)frameSize();
979
980    do {
981        audioBuffer.frameCount = userSize/frameSz;
982
983        // Calling obtainBuffer() with a negative wait count causes
984        // an (almost) infinite wait time.
985        status_t err = obtainBuffer(&audioBuffer, -1);
986        if (err < 0) {
987            // out of buffers, return #bytes written
988            if (err == status_t(NO_MORE_BUFFERS))
989                break;
990            return ssize_t(err);
991        }
992
993        size_t toWrite;
994
995        if (mFormat == AUDIO_FORMAT_PCM_8_BIT && !(mFlags & AUDIO_POLICY_OUTPUT_FLAG_DIRECT)) {
996            // Divide capacity by 2 to take expansion into account
997            toWrite = audioBuffer.size>>1;
998            // 8 to 16 bit conversion
999            int count = toWrite;
1000            int16_t *dst = (int16_t *)(audioBuffer.i8);
1001            while(count--) {
1002                *dst++ = (int16_t)(*src++^0x80) << 8;
1003            }
1004        } else {
1005            toWrite = audioBuffer.size;
1006            memcpy(audioBuffer.i8, src, toWrite);
1007            src += toWrite;
1008        }
1009        userSize -= toWrite;
1010        written += toWrite;
1011
1012        releaseBuffer(&audioBuffer);
1013    } while (userSize >= frameSz);
1014
1015    return written;
1016}
1017
1018// -------------------------------------------------------------------------
1019
1020bool AudioTrack::processAudioBuffer(const sp<AudioTrackThread>& thread)
1021{
1022    Buffer audioBuffer;
1023    uint32_t frames;
1024    size_t writtenSize;
1025
1026    mLock.lock();
1027    // acquire a strong reference on the IMemory and IAudioTrack so that they cannot be destroyed
1028    // while we are accessing the cblk
1029    sp <IAudioTrack> audioTrack = mAudioTrack;
1030    sp <IMemory> iMem = mCblkMemory;
1031    audio_track_cblk_t* cblk = mCblk;
1032    mLock.unlock();
1033
1034    // Manage underrun callback
1035    if (mActive && (cblk->framesAvailable() == cblk->frameCount)) {
1036        LOGV("Underrun user: %x, server: %x, flags %04x", cblk->user, cblk->server, cblk->flags);
1037        if (!(android_atomic_or(CBLK_UNDERRUN_ON, &cblk->flags) & CBLK_UNDERRUN_MSK)) {
1038            mCbf(EVENT_UNDERRUN, mUserData, 0);
1039            if (cblk->server == cblk->frameCount) {
1040                mCbf(EVENT_BUFFER_END, mUserData, 0);
1041            }
1042            if (mSharedBuffer != 0) return false;
1043        }
1044    }
1045
1046    // Manage loop end callback
1047    while (mLoopCount > cblk->loopCount) {
1048        int loopCount = -1;
1049        mLoopCount--;
1050        if (mLoopCount >= 0) loopCount = mLoopCount;
1051
1052        mCbf(EVENT_LOOP_END, mUserData, (void *)&loopCount);
1053    }
1054
1055    // Manage marker callback
1056    if (!mMarkerReached && (mMarkerPosition > 0)) {
1057        if (cblk->server >= mMarkerPosition) {
1058            mCbf(EVENT_MARKER, mUserData, (void *)&mMarkerPosition);
1059            mMarkerReached = true;
1060        }
1061    }
1062
1063    // Manage new position callback
1064    if (mUpdatePeriod > 0) {
1065        while (cblk->server >= mNewPosition) {
1066            mCbf(EVENT_NEW_POS, mUserData, (void *)&mNewPosition);
1067            mNewPosition += mUpdatePeriod;
1068        }
1069    }
1070
1071    // If Shared buffer is used, no data is requested from client.
1072    if (mSharedBuffer != 0) {
1073        frames = 0;
1074    } else {
1075        frames = mRemainingFrames;
1076    }
1077
1078    int32_t waitCount = -1;
1079    if (mUpdatePeriod || (!mMarkerReached && mMarkerPosition) || mLoopCount) {
1080        waitCount = 1;
1081    }
1082
1083    do {
1084
1085        audioBuffer.frameCount = frames;
1086
1087        // Calling obtainBuffer() with a wait count of 1
1088        // limits wait time to WAIT_PERIOD_MS. This prevents from being
1089        // stuck here not being able to handle timed events (position, markers, loops).
1090        status_t err = obtainBuffer(&audioBuffer, waitCount);
1091        if (err < NO_ERROR) {
1092            if (err != TIMED_OUT) {
1093                LOGE_IF(err != status_t(NO_MORE_BUFFERS), "Error obtaining an audio buffer, giving up.");
1094                return false;
1095            }
1096            break;
1097        }
1098        if (err == status_t(STOPPED)) return false;
1099
1100        // Divide buffer size by 2 to take into account the expansion
1101        // due to 8 to 16 bit conversion: the callback must fill only half
1102        // of the destination buffer
1103        if (mFormat == AUDIO_FORMAT_PCM_8_BIT && !(mFlags & AUDIO_POLICY_OUTPUT_FLAG_DIRECT)) {
1104            audioBuffer.size >>= 1;
1105        }
1106
1107        size_t reqSize = audioBuffer.size;
1108        mCbf(EVENT_MORE_DATA, mUserData, &audioBuffer);
1109        writtenSize = audioBuffer.size;
1110
1111        // Sanity check on returned size
1112        if (ssize_t(writtenSize) <= 0) {
1113            // The callback is done filling buffers
1114            // Keep this thread going to handle timed events and
1115            // still try to get more data in intervals of WAIT_PERIOD_MS
1116            // but don't just loop and block the CPU, so wait
1117            usleep(WAIT_PERIOD_MS*1000);
1118            break;
1119        }
1120        if (writtenSize > reqSize) writtenSize = reqSize;
1121
1122        if (mFormat == AUDIO_FORMAT_PCM_8_BIT && !(mFlags & AUDIO_POLICY_OUTPUT_FLAG_DIRECT)) {
1123            // 8 to 16 bit conversion
1124            const int8_t *src = audioBuffer.i8 + writtenSize-1;
1125            int count = writtenSize;
1126            int16_t *dst = audioBuffer.i16 + writtenSize-1;
1127            while(count--) {
1128                *dst-- = (int16_t)(*src--^0x80) << 8;
1129            }
1130            writtenSize <<= 1;
1131        }
1132
1133        audioBuffer.size = writtenSize;
1134        // NOTE: mCblk->frameSize is not equal to AudioTrack::frameSize() for
1135        // 8 bit PCM data: in this case,  mCblk->frameSize is based on a sampel size of
1136        // 16 bit.
1137        audioBuffer.frameCount = writtenSize/mCblk->frameSize;
1138
1139        frames -= audioBuffer.frameCount;
1140
1141        releaseBuffer(&audioBuffer);
1142    }
1143    while (frames);
1144
1145    if (frames == 0) {
1146        mRemainingFrames = mNotificationFramesAct;
1147    } else {
1148        mRemainingFrames = frames;
1149    }
1150    return true;
1151}
1152
1153// must be called with mLock and cblk.lock held. Callers must also hold strong references on
1154// the IAudioTrack and IMemory in case they are recreated here.
1155// If the IAudioTrack is successfully restored, the cblk pointer is updated
1156status_t AudioTrack::restoreTrack_l(audio_track_cblk_t*& cblk, bool fromStart)
1157{
1158    status_t result;
1159
1160    if (!(android_atomic_or(CBLK_RESTORING_ON, &cblk->flags) & CBLK_RESTORING_MSK)) {
1161        LOGW("dead IAudioTrack, creating a new one from %s TID %d",
1162             fromStart ? "start()" : "obtainBuffer()", gettid());
1163
1164        // signal old cblk condition so that other threads waiting for available buffers stop
1165        // waiting now
1166        cblk->cv.broadcast();
1167        cblk->lock.unlock();
1168
1169        // refresh the audio configuration cache in this process to make sure we get new
1170        // output parameters in getOutput_l() and createTrack_l()
1171        AudioSystem::clearAudioConfigCache();
1172
1173        // if the new IAudioTrack is created, createTrack_l() will modify the
1174        // following member variables: mAudioTrack, mCblkMemory and mCblk.
1175        // It will also delete the strong references on previous IAudioTrack and IMemory
1176        result = createTrack_l(mStreamType,
1177                               cblk->sampleRate,
1178                               mFormat,
1179                               mChannelMask,
1180                               mFrameCount,
1181                               mFlags,
1182                               mSharedBuffer,
1183                               getOutput_l(),
1184                               false);
1185
1186        if (result == NO_ERROR) {
1187            uint32_t user = cblk->user;
1188            uint32_t server = cblk->server;
1189            // restore write index and set other indexes to reflect empty buffer status
1190            mCblk->user = user;
1191            mCblk->server = user;
1192            mCblk->userBase = user;
1193            mCblk->serverBase = user;
1194            // restore loop: this is not guaranteed to succeed if new frame count is not
1195            // compatible with loop length
1196            setLoop_l(cblk->loopStart, cblk->loopEnd, cblk->loopCount);
1197            if (!fromStart) {
1198                mCblk->bufferTimeoutMs = MAX_RUN_TIMEOUT_MS;
1199                // Make sure that a client relying on callback events indicating underrun or
1200                // the actual amount of audio frames played (e.g SoundPool) receives them.
1201                if (mSharedBuffer == 0) {
1202                    uint32_t frames = 0;
1203                    if (user > server) {
1204                        frames = ((user - server) > mCblk->frameCount) ?
1205                                mCblk->frameCount : (user - server);
1206                        memset(mCblk->buffers, 0, frames * mCblk->frameSize);
1207                    }
1208                    // restart playback even if buffer is not completely filled.
1209                    android_atomic_or(CBLK_FORCEREADY_ON, &mCblk->flags);
1210                    // stepUser() clears CBLK_UNDERRUN_ON flag enabling underrun callbacks to
1211                    // the client
1212                    mCblk->stepUser(frames);
1213                }
1214            }
1215            if (mActive) {
1216                result = mAudioTrack->start();
1217                LOGW_IF(result != NO_ERROR, "restoreTrack_l() start() failed status %d", result);
1218            }
1219            if (fromStart && result == NO_ERROR) {
1220                mNewPosition = mCblk->server + mUpdatePeriod;
1221            }
1222        }
1223        if (result != NO_ERROR) {
1224            android_atomic_and(~CBLK_RESTORING_ON, &cblk->flags);
1225            LOGW_IF(result != NO_ERROR, "restoreTrack_l() failed status %d", result);
1226        }
1227        mRestoreStatus = result;
1228        // signal old cblk condition for other threads waiting for restore completion
1229        android_atomic_or(CBLK_RESTORED_ON, &cblk->flags);
1230        cblk->cv.broadcast();
1231    } else {
1232        if (!(cblk->flags & CBLK_RESTORED_MSK)) {
1233            LOGW("dead IAudioTrack, waiting for a new one TID %d", gettid());
1234            mLock.unlock();
1235            result = cblk->cv.waitRelative(cblk->lock, milliseconds(RESTORE_TIMEOUT_MS));
1236            if (result == NO_ERROR) {
1237                result = mRestoreStatus;
1238            }
1239            cblk->lock.unlock();
1240            mLock.lock();
1241        } else {
1242            LOGW("dead IAudioTrack, already restored TID %d", gettid());
1243            result = mRestoreStatus;
1244            cblk->lock.unlock();
1245        }
1246    }
1247    LOGV("restoreTrack_l() status %d mActive %d cblk %p, old cblk %p flags %08x old flags %08x",
1248         result, mActive, mCblk, cblk, mCblk->flags, cblk->flags);
1249
1250    if (result == NO_ERROR) {
1251        // from now on we switch to the newly created cblk
1252        cblk = mCblk;
1253    }
1254    cblk->lock.lock();
1255
1256    LOGW_IF(result != NO_ERROR, "restoreTrack_l() error %d TID %d", result, gettid());
1257
1258    return result;
1259}
1260
1261status_t AudioTrack::dump(int fd, const Vector<String16>& args) const
1262{
1263
1264    const size_t SIZE = 256;
1265    char buffer[SIZE];
1266    String8 result;
1267
1268    result.append(" AudioTrack::dump\n");
1269    snprintf(buffer, 255, "  stream type(%d), left - right volume(%f, %f)\n", mStreamType, mVolume[0], mVolume[1]);
1270    result.append(buffer);
1271    snprintf(buffer, 255, "  format(%d), channel count(%d), frame count(%d)\n", mFormat, mChannelCount, mCblk->frameCount);
1272    result.append(buffer);
1273    snprintf(buffer, 255, "  sample rate(%d), status(%d), muted(%d)\n", (mCblk == 0) ? 0 : mCblk->sampleRate, mStatus, mMuted);
1274    result.append(buffer);
1275    snprintf(buffer, 255, "  active(%d), latency (%d)\n", mActive, mLatency);
1276    result.append(buffer);
1277    ::write(fd, result.string(), result.size());
1278    return NO_ERROR;
1279}
1280
1281// =========================================================================
1282
1283AudioTrack::AudioTrackThread::AudioTrackThread(AudioTrack& receiver, bool bCanCallJava)
1284    : Thread(bCanCallJava), mReceiver(receiver)
1285{
1286}
1287
1288bool AudioTrack::AudioTrackThread::threadLoop()
1289{
1290    return mReceiver.processAudioBuffer(this);
1291}
1292
1293status_t AudioTrack::AudioTrackThread::readyToRun()
1294{
1295    return NO_ERROR;
1296}
1297
1298void AudioTrack::AudioTrackThread::onFirstRef()
1299{
1300}
1301
1302// =========================================================================
1303
1304
1305audio_track_cblk_t::audio_track_cblk_t()
1306    : lock(Mutex::SHARED), cv(Condition::SHARED), user(0), server(0),
1307    userBase(0), serverBase(0), buffers(0), frameCount(0),
1308    loopStart(UINT_MAX), loopEnd(UINT_MAX), loopCount(0), volumeLR(0),
1309    sendLevel(0), flags(0)
1310{
1311}
1312
1313uint32_t audio_track_cblk_t::stepUser(uint32_t frameCount)
1314{
1315    uint32_t u = this->user;
1316
1317    u += frameCount;
1318    // Ensure that user is never ahead of server for AudioRecord
1319    if (flags & CBLK_DIRECTION_MSK) {
1320        // If stepServer() has been called once, switch to normal obtainBuffer() timeout period
1321        if (bufferTimeoutMs == MAX_STARTUP_TIMEOUT_MS-1) {
1322            bufferTimeoutMs = MAX_RUN_TIMEOUT_MS;
1323        }
1324    } else if (u > this->server) {
1325        LOGW("stepServer occured after track reset");
1326        u = this->server;
1327    }
1328
1329    if (u >= userBase + this->frameCount) {
1330        userBase += this->frameCount;
1331    }
1332
1333    this->user = u;
1334
1335    // Clear flow control error condition as new data has been written/read to/from buffer.
1336    if (flags & CBLK_UNDERRUN_MSK) {
1337        android_atomic_and(~CBLK_UNDERRUN_MSK, &flags);
1338    }
1339
1340    return u;
1341}
1342
1343bool audio_track_cblk_t::stepServer(uint32_t frameCount)
1344{
1345    if (!tryLock()) {
1346        LOGW("stepServer() could not lock cblk");
1347        return false;
1348    }
1349
1350    uint32_t s = this->server;
1351
1352    s += frameCount;
1353    if (flags & CBLK_DIRECTION_MSK) {
1354        // Mark that we have read the first buffer so that next time stepUser() is called
1355        // we switch to normal obtainBuffer() timeout period
1356        if (bufferTimeoutMs == MAX_STARTUP_TIMEOUT_MS) {
1357            bufferTimeoutMs = MAX_STARTUP_TIMEOUT_MS - 1;
1358        }
1359        // It is possible that we receive a flush()
1360        // while the mixer is processing a block: in this case,
1361        // stepServer() is called After the flush() has reset u & s and
1362        // we have s > u
1363        if (s > this->user) {
1364            LOGW("stepServer occured after track reset");
1365            s = this->user;
1366        }
1367    }
1368
1369    if (s >= loopEnd) {
1370        LOGW_IF(s > loopEnd, "stepServer: s %u > loopEnd %u", s, loopEnd);
1371        s = loopStart;
1372        if (--loopCount == 0) {
1373            loopEnd = UINT_MAX;
1374            loopStart = UINT_MAX;
1375        }
1376    }
1377    if (s >= serverBase + this->frameCount) {
1378        serverBase += this->frameCount;
1379    }
1380
1381    this->server = s;
1382
1383    if (!(flags & CBLK_INVALID_MSK)) {
1384        cv.signal();
1385    }
1386    lock.unlock();
1387    return true;
1388}
1389
1390void* audio_track_cblk_t::buffer(uint32_t offset) const
1391{
1392    return (int8_t *)this->buffers + (offset - userBase) * this->frameSize;
1393}
1394
1395uint32_t audio_track_cblk_t::framesAvailable()
1396{
1397    Mutex::Autolock _l(lock);
1398    return framesAvailable_l();
1399}
1400
1401uint32_t audio_track_cblk_t::framesAvailable_l()
1402{
1403    uint32_t u = this->user;
1404    uint32_t s = this->server;
1405
1406    if (flags & CBLK_DIRECTION_MSK) {
1407        uint32_t limit = (s < loopStart) ? s : loopStart;
1408        return limit + frameCount - u;
1409    } else {
1410        return frameCount + u - s;
1411    }
1412}
1413
1414uint32_t audio_track_cblk_t::framesReady()
1415{
1416    uint32_t u = this->user;
1417    uint32_t s = this->server;
1418
1419    if (flags & CBLK_DIRECTION_MSK) {
1420        if (u < loopEnd) {
1421            return u - s;
1422        } else {
1423            // do not block on mutex shared with client on AudioFlinger side
1424            if (!tryLock()) {
1425                LOGW("framesReady() could not lock cblk");
1426                return 0;
1427            }
1428            uint32_t frames = UINT_MAX;
1429            if (loopCount >= 0) {
1430                frames = (loopEnd - loopStart)*loopCount + u - s;
1431            }
1432            lock.unlock();
1433            return frames;
1434        }
1435    } else {
1436        return s - u;
1437    }
1438}
1439
1440bool audio_track_cblk_t::tryLock()
1441{
1442    // the code below simulates lock-with-timeout
1443    // we MUST do this to protect the AudioFlinger server
1444    // as this lock is shared with the client.
1445    status_t err;
1446
1447    err = lock.tryLock();
1448    if (err == -EBUSY) { // just wait a bit
1449        usleep(1000);
1450        err = lock.tryLock();
1451    }
1452    if (err != NO_ERROR) {
1453        // probably, the client just died.
1454        return false;
1455    }
1456    return true;
1457}
1458
1459// -------------------------------------------------------------------------
1460
1461}; // namespace android
1462
1463